The present invention relates to an image reading device for photographic printing in the photo-processing apparatus. More particularly, the present invention relates to an image reading device for photographic printing for reading the color image stored in the film by the CCD image element.
In the printing device for printing the color image stored in the developed film onto a photosensitive material, the image reading device for photographic printing for reading the color image is used. As this image reading device for photographic printing, there are two kinds of devices, the one using the color CCD image element (hereinafter referred to as "color CCD") and the other using the monochrome CCD color element (hereinafter referred to as "monochrome CCD") to convert it to the color image by the color filter (spectral filter).
The device using the color CCD is generally not used because the spectral characteristics do not match against the sensitive material (paper sensitivity) in the photo devices (printer). On the contrary, the device using the monochrome CCD is, as shown in FIG. 10 and FIG. 11, composed of an optical lens mechanism 101 comprising a zoom lens arranged opposite to the film; a filter rotation disk 102 having color filters, a blue filter B, a green filter G and a red filter R, coaxially in the peripheral direction thereof; and a monochrome CCD 103. Since the light voltage of the respective filters B, G and R is strong in the order of filters R, G and B, the light quantity of respective filters B, G and R is balanced by applying dark ND (Neutral Density) coating to the filter R to restrict the transmitting light quantity and ND coating thinner than that to the filter G, with making the light voltage of the filter B as a reference. Thus, the device using the monochrome CCD has been generally used, since it can obtain necessary spectral characteristics freely by combining color filters.
However, since the film of the ND coating becomes a strong reflection surface, the reflected light on the surface of the monochrome CCD 103 is sometimes reflected by the film of the ND coating to be incident over the monochrome CCD 103. In such a case, there is a problem that a phenomenon to degrade the contrast of the imaging plane of the monochrome CCD 103 (hereinafter referred to as a "flare") tends to be caused. There is further a problem that the light reflected in several times on the surface of the zoom lens reaches the film surface to generate an image being out of focus other than the regular image (hereinafter referred to as a "ghost") tends to be generated. Furthermore, since cut filters 104 for removing the ultraviolet rays and infrared rays are sticked to the color filters of respective filters B, G and R, other than respective spectral transmission films, the boundary plane to be sticked is likely to be the reflection surface, and the parallel degree of the sticked two filters is deteriorated due to the error of adhesive precision, so that the parallel degrees of respective filters B, G and R against the monochrome CCD 103 becomes non-uniform, which causes a problem that color divergence is likely to be caused.
The present invention has been completed under the above background. It is therefore a primary object of the present invention to provide an image reading device for photographic printing which can prevent the occurrence of the flare, ghost and color divergence and can obtain a clear color image.